Jan Barglowski (jan++at++archimedes.vislab.navy.mil)
Wed, 3 Jun 1998 10:15:18 -0700 (PDT)
I just didn't work -- I'd guess the scaling of the inset just isn't right.
When I made the clip texture with RGB (or 888) it works, with 5551 it
didn't. So to make a 5551 I made an RGB cliptexture, then changed it
to 5551 using the to5551 program (/usr/share/Performer/src/tools) and
a custom script.
> I am trying to work with high res insets inside a low res image. When I create
> the clip texture (with mgmosaic) it looks like mgmosaic simply did izoom to my
> low res image to be at the same "resolution" as my high res image and then
> doing the mosaic as usual - Since my low res image is VERY BIG I need a HUGE
> disk for this clip texture. What I assumed to see is that level 0 will only
> have the high res areas and only lower levels will have tiles from the low res
> areas.
> Am I missing something, or is this a bug in mgmosaic?
There are a lot of things to consider. mgmosaic does work well but
every inset is a bit different. First, highest res tiles are not made
for everywhere. For example, if your tile size is 512 (-t 512) and
your inset is outside a 512 pixel border of the lower res image, that
border won't be supersampled. Only areas of the low res image that
are part of the high res image's 512x512 tile should be supersampled.
[I hope that makes sense!]
I have made insets out of 3 levels of resolution (25m, 10m and 2m imagery)
successfully. While the cliptexture turns out to be virtual (>32k),
the lowest res does not have a tile at the highest cliptexture level
for everywhere on the cliptexture.
I'd recommend looking in the Performer Programmer's Guide in the
cliptexure chapter about insets. Also, MultiGen's _In Flight_
newsletter in Spring and Summer '97 had a couple of articles by
Brian Dickens on how mgmosaic makes cliptextures. While they
explain the simplest case of insets, it explains the process well.
jan
p.s. I'm unsubscribing from the Performer list due to a job change
(I'm going to Colorado Springs!) so please email me direct until
Friday, then I'll hook back up with the Performer list when I get
my new email address...
--
Jan Anthony Barglowski jan++at++chinalake.navy.mil
Real-time Computer Graphics http://www1.ridgecrest.ca.us/~jan
Naval Air Warfare Center, China Lake (760) 927-1057
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